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采用不同质量分数的Ni元素的钎料对YG15硬质合金与35Cr Mo钢进行了钎焊,分别研究了Ni元素含量、钎焊温度以及超声作用等因素对钎焊接头微观组织与力学性能的影响。研究表明:钎焊温度为800℃时,随钎料中Ni元素的增加,界面处可获得连续的α-Cu固溶体层;当钎料中Ni元素质量分数为4.7%时,其接头剪切强度最高,为295 MPa;钎焊温度影响Ni元素的扩散行为,从而影响界面处贫Co区的宽度,在温度为730℃时,贫Co区宽度最小,接头剪切强度值最高,为350 MPa;施加超声可以增加贫Co区宽度,降低共晶组织含量,并使WC颗粒迁移进入钎缝金属。当超声时间为30 s时,贫Co区宽度为17.5μm,接头剪切强度为371 MPa,比无超声时接头强度提高6%。
YG15 cemented carbide and 35Cr Mo steel were brazed using Ni brazing filler metal with different mass fraction respectively. The effects of Ni content, brazing temperature and ultrasonic action on the microstructure and mechanical properties of brazed joints were studied . The results show that when the brazing temperature is 800 ℃, the continuous α-Cu solid solution layer is obtained at the interface with the increase of Ni in the brazing filler metal. When the Ni content in the brazing filler metal is 4.7%, the joint shear strength And the maximum is 295 MPa. The brazing temperature affects the diffusion of Ni element, which affects the width of the Co-depleted zone. When the temperature is 730 ℃, the width of the Co-depleted zone is the smallest and the shear strength of the joint is the highest at 350 MPa. Ultrasound can increase the width of depleted Co region, reduce the eutectic structure, and make the WC particles migrate into the brazing seam metal. When the ultrasonic time is 30 s, the width of the poor Co region is 17.5 μm, the shear strength of the joint is 371 MPa, which is 6% higher than the strength of the joint without ultrasound.